I have about 80 plants now, ranging from about 1.5'' to 30'' tall (including pot), in pots that range from about 1.5'' to 10'' wide. (Yes - I anticipate acquiring more!) At this point, the design is only preliminary - as I'm building it, I'm sure that I'll have to modify things.
To accommodate the diverse plant sizes, I created 2 sections. The rear is the larger section, using 2'3'' of the 4', and slopes from 3' to 2'5.25''. The front section uses the other 1'9'', and slopes from 1'8.25'' to 1'3''. I included a shelf in the rear for plants that are too short for the tall section and too wide for the short section. Also, even tho the whole roof is hinged, I know that the depths of the tall section would not be accessible. So, I included a hinged back panel of acrylic, 2' tall, the full length of the unit.
For the roof, I decided on single-ply (which is more transparent than 2-ply) PVC (which costs less than polycarbonate, and blocks the least UV). Most succulents need full sun, and I wanted to mimic growing without a greenhouse. Those that can't handle full sun I intend to put in the middle back section, protected by shade cloth. I choose to pitch the roof at 3/12 (see below for definition of 'pitch') so that it's mostly horizontal, but still allows rain to run off. I could have set it at 2/12, but then, when open (for ventilation) and it rains, it wouldn't run off as quickly.
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